Systemic sclerosis: outcome and long-term follow-up of 429 patients from a single italian centre

Background: Systemic sclerosis (SSc) is a multi-systemic fibrotic disorder with worldwide distribution and high morbidity and mortality. Characteristic features of this disease are widespread vasculopathy, inflammation, autoimmunity, and fibrosis. Objectives: This study investigated survival, risk factors and causes of death in a single centre cohort of patients. Methods: Between May 1973 and February 2010, we enrolled 429 consecutive SSc patients (age=60.2±13.7 years, 88.3% females) in the Rheumatology Clinic of Pisa. Survival was estimated using the Kaplan-Meier method. Multivariate survival analyses were conducted using the Cox model. Data were abstracted by chart review and entered into a database. The demographic and clinical characteristics of SSc patients were compared between those who survived versus those who died in follow-up period. Results: In total, 429 patients were followed for a mean duration of 5.8 years (0.03-33.4), representing 2507 patient-years. At baseline, lcSSc were 71.5%. Clinical features were: 45.7% ACA, 25.4% Scl70; 16.2% overlap; 93.3% peripheral vascular system; 31.7% digital ulcers; 44.3% skin score >14; 15.3% joint involvement. In total, 4.3% muscle involvement; 78.9% oesophagus, 18.7% pulmonary arterial hypertension (PAH), 48.4% lung fibrosis; 19.1% ventricular extrasystole (VE); 22% atrial extrasystole, 5.5% kidney involvement, 2.5% renal crisis, pericardial effusion 7%. 39 patients died (9.1%): 12.8% of deaths resulted from PAH; 17.9% from interstitial lung disease (ILD); 5.1% from scleroderma renal crisis; 15.4% from cancer; 7.7% from infections; 41.1% from other not neoplastic causes. Patients with PAH, ILD, VE, pericardial effusion, skin score >14, Scl70 and ACA showed a significantly worse survival. The Cox model supported the prognostic findings obtained. For PAH hazard ratio was 3.52 (CI95% 1.75-7.08), for ILD 2.62 (CI95% 1.18-5.79), for VE 2.99 (CI95% 1.51-5.90), for pericardial effusion 2.84 (CI95% 1.21-6.70), for Scl70 2.14 (CI95% 1.11-4.13) for ACA 2.65 (CI95% 1.35-5.18), for skin score >14 2.10 (CI95% 1.35-5.34). Conclusions: The study confirms the increased risk of death for PAH, ILD, VE, dcSSc, Scl70 and ACA, skin score >14 and pericardial effusion found in other studies both by means of cumulative survival rates and Cox model which points them as predictors of mortality.